Railway-traffic-controlling apparatus



has once been closed.

Patented Jan. 8, 1929.

PAUL N. BOSSART, OF SWISSVALEPENNSYLVANIA, .ASSTGNOBJ T0 THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, .A CORQPORAVTION 0F PENN- SYLVANIA.

RAILWY-TRAFFIC-CONTROLLING APPARATUS.

Application inea January 29, 1926. seriai- N60. $4,588.

My invention relates to railway trafliccon-V -trolling apparatus, and particularly to apparatus of the type comprising train carried governing means co-operating with devices located at intervals along the trackway, Wore particularly my present invention relates to the train carried portion of such apparatus.

T will describe one `form of apparatus embodying my invention, and will then point out the novelfeatures thereof in claims.

The accompanying drawing is a diagrammatic view illustrating one form of ,railway traliic controlling apparatus embodying my invention.

Referring to the drawing,the reference character 1 designates a track rail of a stretch of railway track'traversed by trains one of which is indicated diagrammatically at V. Suitably mounted on train V is a re ceiver A comprising amagnetizable core 2 having the shape of an inverted letter U. This core is provided with two windings 3 and 4. Located also on the train is a relay R, anda magnet D which controls the Vusual brake mechanism on the train so that the brakes are applied when the magnet is deenergized.

Current is at times supplied to windings 3 and 4 from a suitable source of direct current such as a battery J. A circuit for winding 4 may be traced from battery J vthrough ywires 8 and '9, front contact 10 of relay R,

wires 11 and 12, winding 4 oi' receiver A, Wires 13 and 14, winding ot magnet D, and wires 15 and 16, back to battery J. It will be seen that this circuit is closed only when relay R is energized, under which condition magnet D is energized to prevent an automatic application of the brakes. A circuit for winding 3 may be traced from battery J, through wires 8, 9 and 17, front contact 18 of relay R, wires 19 and 20, winding of relay R, wire 21, winding 3 of receiver A, wires 22 and 14, winding of magnet D and wires land 16, back to battery J. It will be seen that the circuit ust traced is a stick circuit for relay R by means of which the relay is maintained in its energized condition after contact 18 so placed on the core and so connected in these circuits that the magnetic fluxes created by Windings 3 and 4 are currents in thewindings are in opposition. l

Preferably winding 4 has more turns than winding 3 as indicated inthe drawing.

The reierence character K designates a circuit controller comprisingV two normally open y contacts 23 and 24. This circuit controller is operated by a pneumatic relay G comprising a chamber 27, one wall ofV which is a flexible diaphragm 25. Chamber 27 is connected with the atmosphere through -a restrictive oritlce 28. Fluid pressure, usually air, is at times supplied to chamber 27 by an acknowledging' valve HQ Whenvalve H is in its normal position, in which it 1s illustrated 1n the drawing, an acknowledging reservoir 30 is connected throughpipe 31 with a source of fluid Vpressure not shown in the drawing. l/Vhen valve H is reversed, however, reservoir 30 is disconnected from pipe 31 and is connected with chamber `27 through pipe 29. The pressure thussupplied to the relayG forces diaphragm 25 downwardly against the bias exerted by a spring 26, thereby closingV i contacts 23 and 24, which are operatively connected with the diaphragm 25. The pressure thus supplied to chamber 27 is gradually dis` diaphragm- 27 upwardly to its original position thereby re-opening contacts 23 and .2.4 of circuit controller K. n p y.

A signalling device designated by' the reference character S is controlled by circuit 'conthe bell S and contact 23. This shunt pathv passes from wire 8, through wire 9, front ycontact 10 of relay R and .wire 11 to wire 12.

Itis manifest, therefore, thati when circuit controller K is closed, bell S will be operated provided the shunt path including contactlO is open, that is, provided relay R is deenergized, but that the bell will .not be operated if contact 10 is closed.

4sipated to atmosphere through orifice 28 so Y that after ka time interval the spring 26 moves -80 Associated with the bell S is a switch 37 controlled by the operating mechanism ol the bell so that this switch is closed only when the `ergizingthe relay.

l As` shown in the drawing, relayvR'is energizech-sothat current is flowing through relay Ri, \`vindingf3, winding et, and magnet valve D; Acknowledging valve H is in its normal Vposition so that reservoir 3() is charged with fluid pressure, and circuit controller K is open, because diaphragm of relayl G occupies its upper position. The bell y S is therefore vde-energiz'ed and switch 37 is -c-ircuit o'f'tlie core 2 ci the receiver.

open. e

' The train carried apparatusthus far described isl suitable for co-operation with trackwa'y devicesyone ol which is illustrated at Binthe drawing. This device, in the form here shown, is a trackway inductor comprising a magnetizable core rprovided with a winding 6. A plurality ol the inductors B are located at intervals along the trackway and are so disposed that as the train V moves '.-along the-trackway, core 2r o" the receiver' A passes successively over thecores 5 of the trackway rinductors B.

Means are provided forv at times short circuiting the winding 6 of each trackway in- Vducten.r As shown in the drawing, when switch .7 is closed, windiiig 6 is short circui'ted, thereby increasing the leilective reluctance of the core 5 to 'ai-,rapid change ol' flux In actual practice the switch 7 will usually be controlled by tral'lcic conditions in advance.

In exl'olaining the operation ot the apparatus as a whole, l vwill first assume that the train passes a trackway inductor B when the winding 6 thereon is short-circuited. As the receiver A passes this inductor the core 5 of the inductor will be included in vthe magnetic Due, however, to the large effective reluctance of the core 5 to rapid changes in the 'flux therethrough, there will be substantially no change inthe fluit created incore 2 by windings 3 and el. l/Vhen the train passesa trackway inductor having itsv winding short-circui'ted theretore, the'y train carried apparatus is not atlected.- Y

.I will now assume that switch 7 of the trackway inductor is open and that` the train 'V passes'the iii-ductor. As the core 2 passes over core 5, the reluctance ot the magnetic circuit including core 2 is materially decreased. The magnetic flux created by winding l which links winding 3 is therefore substantially increased. This increasing magnetic lluX creates in the circuit including relay R a single cycle oit alternating current one halt of whichl is opposite iii-direction to the current supplied to relay l by battery J and is sutlicient in magnitude to cause this relay to become cle-energized. Thede-energization of relay R interrupts all ol the circuits tor magnet D andso causes an automatic application oi the brakes. At the same timethe opening of front contact 18' of relaylt breaks the stickcircuit lor this relay. rlhe other cir-` cuit ltor the' relay is open at circuit controller K and it iollows that after the receiverA has passed the trackway inductor B the relay R will remain in its cle-energizedcondition.

The engineman may 'forestall an automatic brake application by proper manipulation of the acknowledging valve H. To accomplish this result, he operates valve ll just before the train passes the inductor. Reservoir 3() is then connected with chamber 27, an'd'circuit controller K is closed. rihisihas no elllect on signal El because iront contact 10 of relay R is still closed and signal S is therefore shortcircuited. lil/Then the train passes the inductor however, relay R becomes de-energized as explained hereinbelore. The opening ol front contact 10 breaks' the shunt path around bell S and this bell therefore operates. YIt is manifest .that bell S will not ring unless the relay R actually opens and then only it the engineman has actuated circuit controller K. The operation ol' the bell therefore informs the enginen'ian that the train carried apparatus has 'functioned properly. The energiz'ation of bell S closes switch 37, and it circuit controller'K is still closed, current is supplied to relay R over t'ront contact 211ml: circuit controller l and switch 37. By 'he time this happens the receiver A will have passed the inductoi B and relay lil will again become energized. Magnet D then becomes energized to prevent an automatic application ot the brakes. As soon as front contact 10 ot relay lt closes, bell S is shunted and switch 37 opens. Relay R is new hel d in its energized con dition by its stick circuit, although its pick-up circuit is broken at switch 37.

ln actual practice the brake applying'i-nechanisin controlled by magnet D has a suliicient time interval to insure that the brakes will not be Iapplied during the briel (le-energization of relay R which takes place it the engineman acknowledges as the train passes a trackway inductor. y Y

After the expira-tion ot' the time interval required for the fluid pressure in chamber 27 to become dissipated to atmosphere circuit controller K opens and the apparatus then occupies itsoriginal condition. It should be particularly pointed out that should the enginemade it will be seen that when relay R be-l man operate circuit controller `K too soon',

- thisv circuit controller will re-open'before the switch 37 closes and it will jthereitore beimoperated again.

From the explanation of theV apparatus just comes cle-energized the circuit for winding4 of receivei' A is broken. The winding l has a considerable amount of inductance and under certain conditions it may happen that the sudden interruption of the current through this winding might cause injurious sparking at contact 10. The winding of magnet D also has considerable inductance and since this winding is connected in series with winding l its elifect is added to winding 4L in causing sparking at contact'10f In order to prevent this sparking I prefer to connect a resistance in parallel with winding t of receiver A and the winding of magnet D. I have discovered that an asymmetric unit is a particularly desirable form of resistance for this purpose. One form ofasymmetric unit which is peculiarly adapted for this use is the copper oXide rectifier disclosed in an application for Letters Patent of the United States Serial No. 1,111, filed January 7, 1925, by Lars'O. Gron'dahl, for uni-directional current carrying devices. The asyinmetric unit indicated diagrainmatically in the drawing at 40 is connected in parallel with winding 4 and the winding of magnet D. As the Contact V of relay R opens the collapse of the magnetic field surrounding winding t creates a surge of current which is sliunted away from contact 10' through av circuit'which may-be traced from the rightliand terminal of winding 4 through wires 13 and 111, winding of magnet D, wires l-and Al1, asymmetric unit 40, wires 39, and 12, back to the left-hand terminal of winding 4. The asymmetric unit is so arranged that it offers a smaller resistance to current lowing in the direction just traced than to current flowing in the opposite direction through this circuit. It follows, therefore, that the asymmetric iinit Oilers a high resistance to current from battery J which would ordinarily flow through the unit when contact 10 of relay R is closed. I have discovered that with an asymmetric unit connected as here shown and described, there is substantially no sparking at contact 10 when this contact opens.

One advantage of the apparatus embodying my invention is that only one relay is used on board the train in place of a plurality of relays which have been used for vsimilar purposes in railway traffic controlling apparatus suggested.

Although I have herein shown and described only one form of railway trailic controlling apiliaratus embodying my invention, it isunderstood that variouschanges `and iiiodilications may be made therein within the lscope of the appended claimswithout departing frointlie spirit and scope of myinvention. Having thus described my invention, what I claim is: i y b v1. In railway traffic controlling apparatus comprising a train carried magnetizablecore, provided with two windings and means in the trackway for at times varying the reluctance of tlieinagnetic circuit through said-core,fthe combination of a relay, a magnet for controlling the brakes on the train, a source of direct current,-means for connecting one terminal of said source with a terminal of onesaid winding through said 'relay and a frontV contact ot the relay, Vmeans for connecting said one terminal ot' the sourcewith a terminal of tlie'remaiiiing winding through a frontcontact of said'relay, and means for connecting ,y the tree terminals of both said windings with the remaining terminal of said source through said magnet.

2. In railway traic controlling apparatus comprising a train carried magnetizable core provided with two windingsand means in the trackway for at times varying the reluc-A tance oi the magnetic circuit through said core, the combination of a relay,a` magnet for controlling thebrakes on 'thetrain,: a source et direct current, 'a circuit yfor said magnet including one of said windings and controlled by a contact of said relay; a circuit for said relay including said-source, the other said winding, and a front contact on said re'- s lay; a manually controlled circuit controller;

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a normally open switch'arranged to be closed when said circuit controller is operated provided said relay is open; and a second circuit for said relay including said switch, said source, and said other winding. i

In vrailway traffic controlling apparatus vcomprising a train carried inagnetizable core provided with two windings and means in the trackway for at times varying thereluctance of the magnetic circuit through said coi'e, the combination oi a. relay, a magnet for controlling the brakes on the train, a source of direct current, af circuit for said magnet including one of said windings and 'controlled by a contact of said relay; a circuit for said relay including said source, the other said winding, and a front contact on said relay; a

manually controlled circuit controller, a normally open switch arranged to be closed when Vsaid circuit controller is ope ated provided said relay isvopen; and a second circuit for said relay including said switch, said source, said other winding, and a contact of said cir- .cuit controller.

Il. In railway tratlic controllingrapparatus comprising a train carried magnetizable coreprovided with two windings and meansr in the trackway `for at times varying the reluctance ot the magnetic circuit through said coie,*tlie combination oi` a relay,fa magnet tor CII controlling the brakes on the train, a source of direct current, a circuit for said magnet` source, the other said winding, and a front contact on said relay; a manually controlled i circuit controller, and a signalling device arranged to be operated when said circuit controller is operated provided said relay is open. 5*.' In railway trailic controlling apparatus comprising a train carried magnetizable core i provided with two windings and means in the itrackway torat times varying the reluctance y of the magnetic circuit through said core, the

combination of a relay, a magnet 'for controlf ling the brakes on the train, a source of vdirect current, a circuit for said magnet inlcluding said source and one of said windings and controlled by a contact of said relay; a a circuit for said relay including` said source, the other said winding, and a front contacten said relay; a manually ycontrolled circuit controller, and a signalling device controlled by said relay and by said circuit controller.-

6. In railway traffic controlling apparatus comprising a train carried magnetizable core provided with two windings and means in the trackway for at times varying the reluctance of the magnetic circuit through said core,the combination of a relay, a magnet for controlling the .brakes on the train, a source of direct current, a circuit for said magnet including said source and one of said windings and.. controlled by a contact ot said relay; a

circuit for said relay including said source, the other said winding, and a front contact on said relay; a manually controlled circuit controller, a normally open switch arranged to be closed when said circuit controller is opv@rated.provided said relay is open, and a shunt around said front contact controlled by said switch.r v

7. ln railway traffic controlling apparatus comprising a train Acarried magnetizable core provided with two windings and means in the trackway for at times varying the reluctance of the lmagnetic circuit" through said. core.,

the combination of a relay, a magnet for controlling the brakeson the train, a source of direct current, a circuit for said magnet including said source and one of said windings and :controlled by a contact of said relay; a circuit for said relay including said source, the other said winding, and a front contact on said relay; a manually controlled circuit controller, a normally open switch arranged to be closed when .said circuit controller is operated provided said relay is open, and a shunt laround said front .contact controlled by Asaid switch and by said circuit controller.

8. Railway traffic controlling apparatus comprising a relay, a magnet for controlling the brakes of a train, a circuit for normally energizing said relay over its own front contact, a circuit for said magnet includinga around said front lcontact including said.

switch and a Contact ot said circuit controller. 9. Railway traffic controlling apparatus comprising a relay, a. magnet for controlling rthe brakes of a train, a circuit for normally energizing said relay over its own front conl tact, a circuit for said magnet including a contact of said relay, means located partly in the trackway for at times cle-energizing said relay, anormally open circuit controller, manually operable means eiiective when operated to close said circuit controller for an interval of time, a normally open switch arranged to be closed when said circuit controller is closed provi-ded said relay is open, and a shunt circuit tor .said yfront contact including said switch and a contact'of said circuit controller. l0. Railway tratiic Acontrolling' apparat-us comprising an inductive winding-on a train, a circuit for said winding including a source ot direct current and a normally closed contact, means for at times opening said contact, andan asymmetric unitl connected in parallel with said winding.

l1. Railway traiiic controlling apparatus comprising an inductive winding on a train, a circuit for said-winding including a source of direct current and afnormally closed con-y tact, means for 'at times opening said contact, and a copper oxide rectiier unit connected in parallel with said winding.

12. Railway trallic controlling apparatus comprising.` an inductive winding yon a train,

a circuit for said winding including a source of ldirect current'and a normally closed contact, means for at times opening said contact, and an asymmetric unit connected in parallel with sai-d winding andt oering a lower re- .sistance tok the transient current 'flowing' through the unit when said contact is opened than to the steady current flowing through the Yunit from saidsonrce when said contact is closed.

13. In railway traiiic controlling apparatus comprising a train magnetizable core provided with two windings and means in the trackway for at times varying the reluctance of the magnetic circuit through said core, the combinationotl a relay, a magnet for controlling the brakes on the train, a circuit for said relay` including a. contact on the relay and one of said winding-s, a circuit for said magnet including the other said win-ding and a contact of said relay, and an asymmetric unit connected inpzarallel with said magnet and said other winding.

14.111 railway trariic controlling apparatus lcqmprising train carried magnetiz- Dit) lili

able core provided with two windings andv means in the trackway for at times Varying the reluctance of the magnetic circuit through said core, the combination of a relay, a magnet for controlling the brakes on the train, a vsource of direct current; a circuit for one of said windings including said source, said magnet, and a front contact of said relay; a circuit for the other sai-d winding including said source, said magnet, the winding of said relay, and a front contact of the relay.

l5. In railway traic controlling apparatus comprising a train carried magnetizfable core provided with two windings and means in the trackway for at times varying the lreluctance of the magneticy circuit` PAUL N. Bossi-tur 

